The Sundance 20 utilizes a swing keel system. This entails a heavy metal keel that is hung on a pivot and can be retracted into the hull to make the boat more easily trailerable. The Keel is raised and lowered by means of a winch system - very similar to the winch used on a boat trailer - with the addition of a clutch system.
The Keel is retracted via a stainless steel cable that is routed through the hull into a hole in the cast keel. this cable should be periodically inspected for fraying, etc… and replaced as necessary.
Per the designer/builder, Len Ferry (Still active on the El Mar Boats FB group), the pivot pin for the Keel is encased in fiberglass during the hull build-up process and is not easily serviceable. If the need arises for it to be replaced, the fiberglass would need to be ground away to give access to the pin.
A couple weeks ago we purchased a used, 1973, El Mar Boat company - Sundance Model 20 , Mono Hull Sailboat.
I’m going to use this area as a repository for any information I can find about these boats.
Some general background:
El Mar Boat Company was founded in Roseville, MI. They produced three models.
Sundance 16 (First produced in 1973)
Sundance 20 (First produced in 1972)
Sundance 23 (First Produced in 1975)
(Much of the data here was found on Sailboatdata.com)
In addition to this, the Sundance 20 also had a “weekender” version which had an extended cabin.